Sergej Milinkovic-Savic is believed to want a move to Chelsea ts summer.
Milinkovic-Savic made his senior debut in Serbia in 2013.
He joined Belgian outfit Genk on a five-year deal the following summer.
The midfielder scored five goals in 24 appearances for the club before agreeing a move to Lazio in 2015.
The 23-year-old scored 12 times in 35 Serie A matches last season.
Milinkovic-Savic represented Serbia at the 2013 UEFA U19 Championship, winning the gold medal. He was one of Serbia’s most influential players at the 2015 FIFA U20 World Cup, as the team won the tournament.
He received his first call-up to the senior squad in 2015 for Serbia’s European Championship qualifiers against Albania and Portugal, but didn’t make his debut until a friendly match against China last October.
Milinkovic-Savic was part of the Serbia squad at this summer’s World Cup in Russia, starting all three group games.